High pressure discharge lamp for e.g. projector or utilization of digital light processing technology as source of light, has bulb and oppositely arranged anode and cathode, which has tungsten with thorium dioxide

摘要

The high pressure discharge lamp has a bulb and oppositely arranged anode (14) and cathode (13). The cathode consists of tungsten, which has thorium dioxide and on its upper outside surface an edge of carbide layer is formed from tungsten carbide. A body (17) is provided with electrode emission material from tungsten which contains thorium dioxide which is joined in a partial area of the outer surface of the cathode. The adjoining range is formed on the cathode and carbide layer is made of tungsten carbide.